Preprint volume - SIBM

Pre-print Volume - Posters
BENTHOS COMMITEE
P. PANETTA, F. MASTROTOTARO, F. CAPEZZUTO, G. SASSANELLI, M. TAVIANI *
Department of Animal and Environmental Biology, University of Bari, Via Orabona, 4 - 70125 Bari, Italia.
f.mastrototaro@biologia.uniba.it
* ISMAR-CNR, Bologna, Via Gobetti, 101 - 40129 Bologna, Italia.
SIZE EVALUATION OF DELECTOPECTEN VITREUS
(MOLLUSCA, BIVALVIA) FROM SANTA MARIA DI LEUCA
DEEP-WATER CORAL SITE (IONIAN SEA)
OSSERVAZIONI SULLA TAGLIA DI UNA POPOLAZIONE
DI DELECTOPECTEN VITREUS (MOLLUSCA, BIVALVIA) PROVENIENTE
DAL SITO A CORALLI PROFONDI DI SANTA MARIA DI LEUCA (MAR IONIO)
Abstract – The size of a Mediterranean population of the deep sea pectinid Delectopecten vitreus
(Mollusca, Bivalvia) is discussed with respect to Atlantic counterparts. The Mediterranean specimens
collected in the Ionian Sea at the Santa Maria di Leuca deep water coral site are characterized by a size
smaller than Atlantic stocks.
Key-words: Delectopecten vitreus, population, deep coral epifauna.
Introduction – Delectopecten vitreus (Gmelin, 1791) is a quasi-cosmopolitan pectinid
bivalve distributed in the Atlantic, Indian and Pacific Ocean, from infralittoral down to
abyssal depths (e.g., Schein, 1989). D. vitreus is characterized by a planktotrophic
development (Dijkstra and Gofas, 2004) and its long-lasting meroplanktonic life
ensures its wide geographic dispersion. The species is rather frequent in the
Mediterranean Sea and living specimens were found byssate on a variety of substrates
(e.g, Smriglio, 2005; Mastrototaro et al., 2010). D. vitreus commonly occurs in the
deep-water Pleistocene record of the Mediterranean basin and this includes also
submerged situations datable to the last glacial epoch (Taviani and Colantoni, 1984; Di
Geronimo et al., 2005). The biology and population structure of Mediterranean D.
vitreus stocks are poorly known. In this contest the size distribution of D. vitreus
specimens collected alive in the Santa Maria di Leuca (SML) deep water coral site
(Ionian Sea) is discussed.
Materials and methods – All live specimens considered in this study were sampled
during various missions of RV Urania and Universitatis, devoted to the study of the
SML coral site (Mastrototaro et al., 2010); they were measured with an electronic
calliper (Total length=TL and total height=TH in mm). The size-frequency distribution
was elaborated considering size classes of 2 mm. The relationship between total length
and total height was tested by means of linear regression. Stereomicroscopic
observations of the external shell morphology were aimed at examining microsculpture
features.
Results – A total of 181 specimens were living-collected, from 451 to 1100 m depth,
either on both artificial substrates (mostly entangled fishing lines or plastic litter) or
dead on scleractinian coral colonies off the Santa Maria di Leuca (SML) deep water
coral site. Such shells are equipped with fragile valves marked by concentric rows of
small scales and vesicles as reported by Schein (1989) as typical for the subspecies D.
vitreus vitreus. The TL ranged from 6 to 16 mm. The length and height were highly
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010
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